# Dark Sky Law: Washington

Washington's 2023 HB 1173 requires new and existing wind energy facilities to use aircraft-detection lighting systems so obstruction lights only activate when aircraft are nearby, instead of staying lit continuously; existing facilities must comply by January 1, 2026. It targets turbine light pollution specifically and does not set general outdoor-lighting or dark-sky rules for other development.

**Status:** limited (checked 2026-09-23)
Washington's 2023 HB 1173 requires new and existing wind energy facilities to use aircraft-detection lighting systems so obstruction lights only activate when aircraft are nearby, instead of staying lit continuously; existing facilities must comply by January 1, 2026. It targets turbine light pollution specifically and does not set general outdoor-lighting or dark-sky rules for other development.

## Statutes
- [Wind turbine aircraft detection lighting systems](http://aprilconnors.houserepublicans.wa.gov/2023/05/09/rep-april-connors-anti-light-pollution-measure-signed-into-law/), 2023 HB 1173 (2023)

## Sources
- http://aprilconnors.houserepublicans.wa.gov/2023/05/09/rep-april-connors-anti-light-pollution-measure-signed-into-law/
- https://lawfilesext.leg.wa.gov/Biennium/2023-24/Htm/Bills/House%20Bills/1173.htm

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Canonical: https://darkskiesdirectory.com/laws/WA